Experimental and Computational Studies on a Base-Free Terminal Uranium Phosphinidene Metallocene.

ABSTRACT: The first stable base-free terminal uranium phosphinidene metallocene is presented; and its structure and reactivity have been studied in detail and compared to that of the corresponding thorium derivative. Salt metathesis reaction of the methyl iodide uranium metallocene Cp'''₂ U(I)Me (2, Cp'''=?⁵ -1,2,4-(Me₃ C)₃ C₅ H₂ ) with Mes*PHK (Mes*=2,4,6-(Me₃ C)₃ C₆ H₂ ) in THF yields the base-free terminal uranium phosphinidene metallocene, Cp'''₂ U=PMes* (3). In addition, density functional theory (DFT) studies suggest substantial 5f orbital contributions to the bonding within the uranium phosphinidene [U]=PAr moiety, which results in a more covalent bonding between the [Cp'''₂ U]²⁺ and [Mes*P]^2- fragments than that for the related thorium derivative. This difference in bonding besides steric reasons causes different reactivity patterns for both molecules. Therefore, the uranium derivative 3 may act as a Cp'''₂ U(II) synthon releasing the phosphinidene moiety (Mes*P:) when treated with alkynes or a variety of hetero-unsaturated molecules such as imines, thiazoles, ketazines, bipy, organic azides, diazene derivatives, ketones, and carbodiimides.

SUBMITTER: Wang D 

PROVIDER: S-EPMC7756876 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature